Odd color eyes

The odd-eyed coloring is caused when either the epistatic (dominant) white gene (which masks any other color genes and turns a cat completely white)[4] or the white spotting gene (which is the gene responsible for bicolor and tuxedo cats)[5] prevents melanin (pigment) granules from reaching one eye during development,[3] resulting in a cat with one blue eye and one green, yellow, or brown eye. The condition only rarely occurs in cats that lack both the dominant white and the white spotting gene
For all kind of animals.
These eyes can be on humans too.